Dynamics of the absorption of pulsed laser radiation in a wide-band impurity semiconductor

摘要

This paper presents the results of numerical modelling of the dynamics of the absorption in a wide-band semiconductor with deep impurity levels when it is acted on by a nanosecond laser pulse with a photon energy less than the band gap but greater than the impurity-ionization energy. It is shown that the dynamics of the impurity-absorption saturation is affected by the intensity and spatial distribution of the radiation. The contribution of two-photon absorption and absorption at minority carriers to the transmittance of the semiconductor in the presence of impurity absorption is considered. A comparison is made with the experimental data for compensated gallium arsenide and zinc selenide with deep levels in the band gap for a radiation wavelength of 1.06 μm.